ANDROID: x86/extable: Do not mark exception callback as CFI

The exception table entries are constructed out of a relative offset
and point to the actual function, not the CFI table entry. For now,
just mark the caller as not checking CFI. The failure is most visible
at boot with CONFIG_DEBUG_RODATA_TEST=y.

Bug: 145210207
Change-Id: Idf6efed424fc95ef20ddd69596478dc813754ce4
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

arch/x86/mm/extable.c

@@ -155,6 +155,7 @@ enum handler_type ex_get_fault_handler_type(unsigned long ip)
 		return EX_HANDLER_OTHER;
 }
 
+__nocfi
 int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,
 		    unsigned long fault_addr)
 {